1. Field of the Invention
The present invention is related to a filter system capable of automatically adjusting bandwidth and a method of automatically adjusting bandwidth of a filter, and particularly to a filter system capable of automatically adjusting bandwidth and a method of automatically adjusting bandwidth of a filter that can utilize an adaptive unit to control the filter for dynamically adjusting the bandwidth of the filter according to a usage mode and/or a surrounding environment of a gravity sensor.
2. Description of the Prior Art
General speaking, for a filter coupled to a gravity sensor of a micro electro-mechanical system (MEMS) circuit, noise of the gravity sensor is generated mainly from the MEMS circuit (such as Brownian motion), analog circuits coupled to the gravity sensor (such as thermal noise, or capacitor coupling noise), and a surrounding environment of the gravity sensor (such as vibration of a user, or mechanical structure for fixing the gravity sensor).
In addition, the user not only considers trade-off between bandwidth of the filter (cut-off frequency) and response time, but also considers different cut-off frequencies corresponding to different applications for gravity and tilt detection. However, in the prior art, the filter can not automatically adjust the bandwidth of the filter (that is, the cut-off frequency of the filter) according to the above mentioned problems. That is to say, in the prior art, the bandwidth of the filter can not be changed properly for the different applications.